The Horticultural Research Institute, in collaboration with AmericanHort, established the Horticultural Industry Bee & Pollinator Stewardship Initiative in 2014. One of the primary goals of the Initiative is to identify and fund research that will help answer key science questions and fill gaps needed to inform, design and refine an industry stewardship program. The Initiative’s focus on research is a key component in establishing a clearer understanding of horticulture’s impact on pollinators.
One researcher who received project funding this year is Dr. Richard Cowles, Connecticut Agricultural Experiment Station (Windsor, Conn.). Cowles is analyzing pesticide residue in pollen and nectar on neonicotinoid-treated plants. Using plants commonly used in the landscape, Cowles expects to further develop an understanding of systemic insecticide update and potential interactions with nectar and pollen. Why is this important? Currently, there are significant gaps in data related to the concentration of systemic insecticides. Establishing whether treated plants (when treated properly) are safe to bees and other pollinators will aid in setting stewardship standards for growers and assist in educating retail sellers and consumers about the practices of growers.
To date, Cowles has embarked upon dose-response tests on minute pirate bugs, using neonicotinoid insecticides and their suggested replacements. An early goal for the project is to establish whether the pirate bugs can be utilized in the bioassays (ie: can the team quantify the insecticide residues in the pirate bugs). His team is further investigating the active ingredients, application methods and application timing relative to flowering as factors that may influence the residues found in nectar and pollen of ornamental plants.
A second project underway is led by Dr. Daniel Potter of the University of Kentucky (Lexington, Ky.). Potter and his team are working to identify best management practices by which producers and landscape managers can protect plants from pests while simultaneously mitigating risks to bees. His research also has the potential to support planting recommendations for landscapes that sustain bees throughout the growing season, identify plants that warrant particular caution when using systemic insecticides and highlight plants whose floral characteristics reduce the potential for bees to be impacted by systemic insecticides.
Potter’s team has already implemented work to assess the extent and longevity of translocation of soil-applied imidacloprid and dinotefuran into nectar and pollen. Flowers from early-blooming species in the project were collected, bagged and transported to a lab where anthers with pollen were removed from each flower by forceps. Flowers were spun in centrifuges to remove nectar. Samples are stored until all three plant species in the project have been sampled. From the lab, they will travel to be analyzed in a blind review for insecticide residues.
Potter’s team has also begun work to document bee assemblages (types of bees, bee species richness and diversity) associated with numerous species of flowering woody ornamentals, and to rate/rank those plants in terms of attractiveness to bees. To achieve this, bees are being sampled from approximately 40 species of common flowering trees and shrubs across multiple sites. Bees are netted, preserved, coiffed in a fan-driven bee drier, pinned, labeled and identified. Comparisons are being made between native and non-native plants, trees versus shrubs, and plants having particular sets of floral characteristics. This is one of the most extensive pollinator surveys ever done on woody plants and, when completed, will form the basis for science-based recommendations for bee-friendly landscape plants.
Three additional pollinator research projects are also underway this year; two receiving funding through HRI’s pollinator initiative, and one receiving funding through HRI’s traditional research grants program. Updates on these projects will be featured in upcoming articles. For additional information about these projects, or any of the several dozen HRI-funded projects currently in progress, please contact Jennifer Gray at 614-884-1155 or Jenniferg@americanhort.org.